激素处理对杜鹃花自交与杂交种子萌发的影响

杜鹃花种子细小且发芽率低,为探索有效促进种子萌发的方法,选用杜鹃花主栽品种春鹃紫蝴蝶自交种子为材料,通过蒸馏水浸种、GA₃浸种和无菌播种添加NAA、KT、ZT及GA₃的处理方式,比较不同处理对杜鹃花自交种子萌发时间、发芽率等指标的影响。结果表明,蒸馏水浸种处理以24 h浸种的效果最佳,发芽率达43%;无菌播种结合2.0 mg·L^-1 GA₃+0.05 mg·L^-1 NAA处理的效果最佳,发芽率达75%;GA₃浸种以1 600 mg·L^-1 GA₃处理24 h的效果最佳,发芽率可达82%,是对照组的1.82倍。以GA₃浸种法处理杜鹃花2个杂交组合的杂交种子,发现其各项发芽指标均优于对照,其中29号杂交种子的最适GA₃处理为1 200 mg·L^-1浸种24 h,发芽率达96%;59号杂交种子最适GA₃处理为1 600 mg·L^-1浸种24 h,发芽率可达95%,二者发芽率分别比对照提高20%和71%,萌发时间分别提早2和8 d。因此,适宜浓度尤其是高浓度GA₃浸种处理能有效促进杜鹃花自交和杂交种子的萌发。

Effects of hormone treatments on germination of self-pollinated seeds and hybrid seeds of azalea cultivars

To find an efficient way to promote seed germination of azaleas, whose seeds were very small and had low germination, self-pollinated seeds from azalea cultivar Zihudie were treated in three ways: 1) water soaking for 6 to 48 h; 2) 100 to 2 000 mg·L^-1 GA₃ soaking for 24 h; 3) cultured in 1/4 MS medium with different combinations of NAA, KT, ZT and GA₃. Then seed germination status of these treatments, including germination time, germination rate and other indicators were compared. The results showed that germination rate of seeds reached 43% when water soaking 24 h and the germination rate increased to 75% when aseptic seeding with 2.0 mg·L^-1 GA₃+0.05 mg·L^-1 NAA. Soaking seeds with 1 600 mg·L^-1GA₃ for 24 h increased the germination rate to 82%, which was 1.82 times as that of the control. Then this GA₃ soaking treatment was set on seeds got from two cross breeding of azalea cultivars which named NO.29 and NO.59. The results showed that when treated with different concentrations of GA₃ for 24 h, germination rate and related index of these two hybrid seeds were superior to those of the controls. Additionally, when the seeds of NO.29 were soaked with 1 200 mg·L^-1 GA₃ for 24 h, the germination rate was 96%. As for NO.59, the germination rate was 95% when the seeds were soaked with 1 600 mg·L^-1GA₃ for 24 h. The seeds germinated 2 and 7 d earlier than the controls, and their germination rates increased 20% and 71% than the controls, respectively. Thus, this treatment especially high concentration of GA₃ soaking was efficient in promoting germination for both self-pollinated seeds and hybrid seeds of azalea cultivars.